As mentioned in the issue, it ispossible that someone could register a color sequence called something like "rygbk" and then it would be ambiguous whether to use the color sequence or interpret as single character colors. We agreed that the color sequence would take precedence in this situation. Should I actually document that precedence either in the user guide section or in a next-api-changes note? I think in practice it will come up very rarely if at all.

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"closes #0000" is in the body of the PR description tolink the related issue
new and changed code istested
[n/a]Plotting related features are demonstrated in anexample
New Features andAPI Changes are noted with adirective and release note
Documentation complies withgeneral anddocstring guidelines

github-actionsbot added the topic: rcparams label

Mar 26, 2025

rcomer commented

Mar 26, 2025

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lib/matplotlib/mpl-data/matplotlibrc

		# color cycle for plot lines as list of string color specs:
		# single letter, long name, or web-style hex
		#axes.prop_cycle: cycler('color', 'tab10')
		# color cycle for plot lines as either a named color sequence or a list

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rcomerMar 26, 2025

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As well as being more succinct, this saves me 40 microseconds 🚀

In [4]:%timeitvalidate_cycler("cycler('color', 'tab10')")80.9μs ±1.25μsperloop (mean ±std.dev.of7runs,10,000loopseach)In [5]:%timeitvalidate_cycler("cycler('color', ['1f77b4', 'ff7f0e', '2ca02c', 'd62728', '9467bd', '8c564b', 'e377c2', '7f7f7f', 'bcbd22', '17becf'])")122μs ±952nsperloop (mean ±std.dev.of7runs,10,000loopseach)

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		colors = [scalar_validator(v.strip()) for v in s if v.strip()]
		except ValueError as ve:
		ke_msg = str(ke)[1:-1] # strip off quote marks
		raise ValueError(f'{ke_msg} and {ve}')

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rcomerMar 26, 2025•
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I'd welcome any feedback on a better way to do the exception handling here. This works to combine the error messages from the two options (see new test) but I feel like I'm missing something.

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timhoffmMar 26, 2025

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Can't you simply

raise ValueError(f'{s!r} is neither a color sequence name nor can it be interpreted as a list of colors')

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Ah, so my problem was trying to be too clever 😆

rcomer added New feature topic: color/color & colormaps topic: color/cycle and removed topic: color/color & colormaps labels

Mar 26, 2025

rcomer force-pushed thecolor-sequence-rcparam branch from07a01d9 to846e825Compare

March 26, 2025 11:39

timhoffm reviewed

Mar 26, 2025

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I would not bother to discuss the potential ambiguity of color sequence name and single-letter-colors-in-string. AFAIK the potential single letter colors are "rgbcmykw" and it's hard to make reasonable name from that. So I doubt this will ever turn up in practice.

galleries/users_explain/artists/color_cycle.py OutdatedShow resolvedHide resolved

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		colors = [scalar_validator(v.strip()) for v in s if v.strip()]
		except ValueError as ve:
		ke_msg = str(ke)[1:-1] # strip off quote marks
		raise ValueError(f'{ke_msg} and {ve}')

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Can't you simply

raise ValueError(f'{s!r} is neither a color sequence name nor can it be interpreted as a list of colors')

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timhoffm mentioned this pull request

Mar 26, 2025

[MNT]: Cleanup internal import dependencies and initialization logic#29813

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QuLogic reviewed

Mar 27, 2025

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rcomer marked this pull request as draft

March 27, 2025 12:07

ENH: set default color cycle to named color sequence

2065369

rcomer force-pushed thecolor-sequence-rcparam branch from7fd60fc to2065369Compare

March 27, 2025 14:55

rcomer marked this pull request as ready for review

March 27, 2025 16:10

timhoffm approved these changes

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dstansby approved these changes

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lib/matplotlib/mpl-data/matplotlibrc

		#axes.prop_cycle: cycler('color', ['1f77b4', 'ff7f0e', '2ca02c', 'd62728', '9467bd', '8c564b', 'e377c2', '7f7f7f', 'bcbd22', '17becf'])
		# color cycle for plot lines as list of string color specs:
		# single letter, long name, or web-style hex
		#axes.prop_cycle: cycler(color='tab10')